Caffeine Stacking Calculator
Most caffeine calculators only count one drink at a time, but most people stack coffee, an energy drink, and pre-workout in the same day. Add every source you've had to see your real total against safe-limit guidance. Nothing uploaded.
Caffeine Sources Today
Total Caffeine Intake
General guidance only, not personal medical advice. Individual caffeine sensitivity varies.
Learn more: adding up caffeine across the day
How the total is worked out
The calculator adds up the milligrams of every drink or supplement you log and compares the total with a daily reference of 400 mg, or 200 mg if you tick pregnant or breastfeeding. The bar turns yellow at 75% of the reference and red above 100%.
The presets are typical single servings: coffee 95 mg, an espresso shot 63, a standard energy drink 80, a large one 160, pre-workout 200, black tea 40 and soda 40. A coffee, a pre-workout and a large energy drink come to 95 + 200 + 160 = 455 mg, over the 400 mg reference with no soda at all.
What the 400 mg figure is
The FDA's page on how much caffeine is too much says that for most adults the FDA has cited 400 milligrams a day, about two to three 12-ounce cups of coffee, as an amount not generally associated with negative effects. It also says there is wide variation in how sensitive people are to caffeine and how fast they eliminate it.
The same page lists 113 to 247 mg in a 12-ounce regular brewed coffee and 41 to 246 mg in a 12-ounce energy drink, so a bigger cup or a different brand can be well above the preset. Check the label or edit the milligrams for your own drinks.
What the calculator does not do
It only adds up what you log. It does not model how caffeine breaks down over the day, so a dose from the afternoon may still be affecting you in the evening even if your total looks fine. The 200 mg pregnancy figure is a conservative reference. The FDA advises pregnant and breastfeeding people to talk to a healthcare provider about caffeine, and this tool is not medical advice.
FAQ
Is 400 mg a hard limit?
No. It is a general reference for healthy adults, and sensitivity varies a lot. If you have a heart condition or an anxiety disorder, take medication, or are pregnant, ask a doctor what is right for you.
Why is the pregnancy reference lower?
The calculator uses 200 mg as a cautious figure for pregnancy and breastfeeding. The FDA says to discuss caffeine with a healthcare provider, so follow your own provider's advice over this number.
Does the calculator track caffeine through the day?
No. It totals the milligrams you enter against the daily reference and does not model how caffeine wears off. If you are sensitive late in the day, count the timing of your doses yourself.